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| author | Chuck Ebbert <76306.1226@compuserve.com> | 2006-09-26 10:52:33 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:33 +0200 |
| commit | 2ade2920dcefdf5595c6380ebed131c964190855 (patch) | |
| tree | 053542af977e5c402633771bb737f3d8a0efef33 /arch/x86_64/kernel | |
| parent | 91cd444e56ebe0c2acd9576a045d77490b26f607 (diff) | |
| download | blackbird-op-linux-2ade2920dcefdf5595c6380ebed131c964190855.tar.gz blackbird-op-linux-2ade2920dcefdf5595c6380ebed131c964190855.zip | |
[PATCH] i386/x86-64: rename is_at_popf(), add iret to tests and fix
is_at_popf() needs to test for the iret instruction as well as
popf. So add that test and rename it to is_setting_trap_flag().
Also change max insn length from 16 to 15 to match reality.
LAHF / SAHF can't affect TF, so the comment in x86_64 is removed.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/kernel')
| -rw-r--r-- | arch/x86_64/kernel/ptrace.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c index 412c6a8bf906..addc14af0c56 100644 --- a/arch/x86_64/kernel/ptrace.c +++ b/arch/x86_64/kernel/ptrace.c @@ -116,17 +116,17 @@ unsigned long convert_rip_to_linear(struct task_struct *child, struct pt_regs *r return addr; } -static int is_at_popf(struct task_struct *child, struct pt_regs *regs) +static int is_setting_trap_flag(struct task_struct *child, struct pt_regs *regs) { int i, copied; - unsigned char opcode[16]; + unsigned char opcode[15]; unsigned long addr = convert_rip_to_linear(child, regs); copied = access_process_vm(child, addr, opcode, sizeof(opcode), 0); for (i = 0; i < copied; i++) { switch (opcode[i]) { - /* popf */ - case 0x9d: + /* popf and iret */ + case 0x9d: case 0xcf: return 1; /* CHECKME: 64 65 */ @@ -189,10 +189,8 @@ static void set_singlestep(struct task_struct *child) * ..but if TF is changed by the instruction we will trace, * don't mark it as being "us" that set it, so that we * won't clear it by hand later. - * - * AK: this is not enough, LAHF and IRET can change TF in user space too. */ - if (is_at_popf(child, regs)) + if (is_setting_trap_flag(child, regs)) return; child->ptrace |= PT_DTRACE; |
